No abstract

In this study, leaves and stems of Talinum triangulare were sequentially extracted with phosphate buffer solution to obtain PTL and PTS (phosphate buffered extracts of T. triangulare leaves and stems), with 75% ethanol to obtained ETL and ETS (ethanol extracts of T. triangulare leaves and stems), or with 90°C boiling water to obtain WTL and WTS (water extracts of T. triangulare leaves and stems). We investigated the antioxidant activities of various T. triangulare extracts, analyzed the extracts' stimulations on human mononuclear cell (MNC) growth and secretion of cytokines (interleukin-1 beta, interferon-γ, and tumor necrosis factor-α) and nitric oxide, and then assayed their subsequent inhibitions on human leukemic U937 cell growth. Results indicated that extracts of T. triangulare showed significant antioxidant activities. Among these extracts, WTS showed the highest stimulatory effect on human MNC growth. The secretion levels of interleukin-1 beta, interferon-γ, and tumor necrosis factor-α in the conditioned medium, wherein human MNC was treated with 500 μg/mL WTS for 72 hours, were 1275, 859, and 2222 pg/mL, respectively. All conditioned media obtained from human MNCs cultured with various T. triangulare extracts showed significant inhibition against U937 cell growth of over 40%. These results suggest that T. triangulare extracts may be used in health foods for their immunomodulatory potential.

Many species of the genus Phellinus possess beneficial properties, including antioxidant, immune-enhancing, and antimutagenic effects. Phenolic compounds and polysaccharides are two kinds of bioactive compounds; however, few studies have compared the differences between Phellinus igniarius and Phellinus linteus in their functional components, functional activities, and nutrient compositions. Herein, the proximate compositions and microelements of the fruiting body of P. igniarius and P. linteus were determined. The fruiting body of P. igniarius and P. linteus were extracted by boiling water [water extract of P. igniarius (WEPI) and P. linteus (WEPL)]. The contents of total phenolics and polysaccharides, as well as superoxide dismutase (SOD)-like and antimutagenic activities of WEPI and WEPL, were compared. We found that WEPI was rich in phenolics and polysaccharides and had higher SOD-like activity than WEPL. Nutrient compositions were mainly different in minerals, whereas anitmutagenicity was similar. All of these results suggested that P. igniarius has greater potential for the development of antioxidant and immunomodulating food products than P. linteus.